Method for manufacturing semiconductor memory device and semiconductor memory device
According to one embodiment, a method for manufacturing a semiconductor memory device includes simultaneously forming a plurality of first holes and a plurality of second holes in a stacked body. The stacked body includes a plurality of first layers and a plurality of second layers. The method includes etching a portion between the second holes next to each other in the stacked body, and connecting at least two or more second holes to form a groove. The method includes forming a film including a charge storage film on a sidewall of the first holes. The method includes forming a channel film on a sidewall of the film including the charge storage film.
1. A method for manufacturing a semiconductor memory device, comprising:
forming, in a stacked body including a plurality of first layers stacked in a first direction and spaced apart from each other, holes through the stacked body in the first direction, the holes including a first hole, a second hole adjacent to the first hole in a second direction orthogonal to the first direction, and a third hole adjacent to the first hole in a third direction orthogonal to the first direction and oblique to the second direction;
after forming holes, etching at least a first inter-position of the stacked body between the first hole and the second hole, a second inter-position of the stacked body between the first hole and the third hole, and a third inter-position of the stacked body between the second hole and the third hole; and
forming a separation portion separating the stacked body in a fourth direction orthogonal to the first direction and the second direction, the separation portion occupying at least positions of the first to third holes and the first to third inter-positions,
wherein
the holes formed in the stacked body include a first row of the holes and a second row of the holes, the first row and the second row being arranged in the fourth direction and the holes of each row being arranged in the second direction,
the separation portion occupies a position of the first row of the holes and a position of the second row of the holes,
the holes formed in the stacked body further include a third row of the holes, the second row and the third row being arranged in the fourth direction, and
the separation portion further occupies a position of the third row of the holes.
2. The method according to claim 1 , wherein
the holes formed in the stacked body further include a fourth hole adjacent to the second hole in the third direction and adjacent to the third hole in the second direction,
etching at least first to third inter-positions further includes etching a fourth inter-position of the stacked body between the second hole and the fourth hole, and a fifth inter-position of the stacked body between the third hole and the fourth hole, and
the separation portion further occupies a position of the fourth hole and the fourth and fifth inter-positions.
3. The method according to claim 1 , wherein the first to third rows of the holes are arrayed in a hounds tooth pattern in the stacked body.
4. The method according to claim 1 , wherein
the holes formed in the stacked body further include an array of the holes other than the first to third holes, the array of the holes and the first to third holes being arranged in the fourth direction.
5. The method according to claim 1 , wherein etching at least first to third inter-positions is performed by a dry etching method.
6. The method according to claim 1 , wherein a minimum width of the separation portion in the fourth direction is larger than a diameter of each of the first to third holes.
7. The method according to claim 1 , wherein forming a separation portion includes forming an insulating film on a sidewall of a trench in the stacked body and burying a conductive film inside the insulating film in the trench.
8. A method for manufacturing a semiconductor memory device, comprising:
forming, in a first region and a second region of a stacked body including a plurality of first layers stacked in a first direction and spaced apart from each other, holes through the stacked body in the first direction, the holes including, in the first region, a first hole, a second hole adjacent to the first hole in a second direction orthogonal to the first direction, and a third hole adjacent to the first hole in a third direction orthogonal to the first direction and oblique to the second direction, and including, in the second region, memory holes in which a channel film is to be formed, the first region and the second region being arranged in a fourth direction orthogonal to the first direction and the second direction, the holes including the first to third holes and the memory holes being periodically formed over the first direction and the second direction;
after forming holes, etching at least a first inter-position of the stacked body between the first hole and the second hole, a second inter-position of the stacked body between the first hole and the third hole, and a third inter-position of the stacked body between the second hole and the third hole; and
forming a separation portion separating the stacked body in the fourth direction, the separation portion occupying at least positions of the first to third holes and the first to third inter-positions.
9. The method according to claim 8 , wherein
the holes formed in the first region further include a fourth hole adjacent to the second hole in the third direction and adjacent to the third hole in the second direction,
etching at least first to third inter-positions further includes etching a fourth inter-position of the stacked body between the second hole and the fourth hole, and a fifth inter-position of the stacked body between the third hole and the fourth hole, and
the separation portion further occupies a position of the fourth hole and the fourth and fifth inter-positions.
10. The method according to claim 8 , wherein
the holes formed in the first region include a first row of the holes and a second row of the holes, the first row and the second row being arranged in the fourth direction and the holes of each row being arranged in the second direction, and
the separation portion occupies a position of the first row of the holes and a position of the second row of the holes.
11. The method according to claim 10 , wherein
the holes formed in the first region further include a third row of the holes, the second row and the third row being arranged in the fourth direction, and
the separation portion further occupies a position of the third row of the holes.
12. The method according to claim 8 , wherein the first to third holes formed in the first region and the memory holes formed in the second region are arrayed in a hounds tooth pattern in the stacked body.
13. The method according to claim 8 , wherein the first to third holes and the memory holes are formed simultaneously.
14. The method according to claim 8 , wherein a diameter of each of the first to third holes and a diameter of each of the memory holes are substantially equal to each other.
15. The method according to claim 8 , wherein etching at least first to third inter-positions is performed by a dry etching method.
16. The method according to claim 8 , wherein a minimum width of the separation portion in the fourth direction is larger than a diameter of each of the memory holes.
17. The method according to claim 8 , wherein forming a separation portion includes forming an insulating film on a sidewall of a trench in the stacked body and burying a conductive film inside the insulating film in the trench.
18. The method according to claim 8 , further comprising:
forming a wiring line electrically connected to the channel film and extending in the fourth direction above the stacked body.